Browse Topic: Hydraulic motors
This test code describes tests for determining characteristics of hydraulic positive displacement motors as used on off-road self-propelled work machines as referenced in SAE J1116.
The techniques outlined in this SAE Recommended Practice were developed as part of an overall program for determining and evaluating fuel consumption of heavy-duty trucks and buses, but it is applicable to off highway vehicles as well. It is recommended that the specific operating conditions be carefully reviewed on the basis of actual installation data. Cooling requirements are affected by all heat exchangers that are cooled by the fan drive system. These may include radiators, condensers, charge air coolers, oil coolers, and others. Because of the variation in size, shape, configuration, and mountings available in cooling fans and fan drive systems, specific test devices have not been included. Using known power/speed relationships for a given fan, this procedure can be used to calculate the fan drive system’s power consumption for cooling systems using the types of drives listed below. This power consumption may then be used in determining engine net power per SAE J1349. For more
This SAE Aerospace Information Report (AIR) provides descriptions of trimmable horizontal stabilizer actuators that are installed on a variety of transport and business aircraft systems.
This SAE Aerospace Recommended Practice (ARP) is an application guide for fixed and variable displacement hydraulic motors. It provides details of the characteristics of fixed and variable displacement hydraulic motors, architectures, circuit designs, controls, and typical applications. The applications include airborne and defense vehicles with emphasis on high performance applications.
This SAE Aerospace Standard (AS) provides a system of graphic symbols and line codings that are intended primarily for usage in hydraulic and pneumatic system schematic diagrams for all types of aircraft.
This SAE Aerospace Recommended Practice (ARP) provides definitions and background information regarding the physical performance and testing of electrohydraulic flow control and pressure control servovalves. This ARP also provides extensive guidance for the preparation of procurement specifications and for functional testing. NOTE: An example of a procurement specification is provided as Appendix A.
This test code describes tests for determining characteristics of hydraulic positive displacement motors as used on off-road self-propelled work machines as referenced in SAE J1116.
To describe laboratory methods for determining and reporting the contaminant level of the wetted portion of hydraulic fluid power components, parts, subsystems and systems, and of fill fluids. For each type of item, it provides a method of obtaining the liquid sample and the contamination level thereof. It also includes procedures for establishing a sampling plan and guidelines for establishing levels of acceptance, but does not set those levels.
SAE J1362 presents graphical symbols for use on operator controls and other displays on off-road work machines as defined in SAE J1116 plus mobile cranes but excluding agricultural tractors. Symbols for agricultural tractors are covered by ASABE S304, ISO 3767-1, and ISO 3767-2.
This Specification covers constant displacement hydraulic motors, generally remotely mounted, using hydraulic fluid under pressure as the energy transfer medium for driving various accessories. Hydraulic motors shall be suitable for use in aircraft hydraulic systems conforming to and as defined in MIL-H-5440 and MIL-H-8891 as applicable.
This SAE Aerospace Information Report (AIR) provides design information of various contemporary aircraft fly-by-wire (FBW) flight control actuation systems that may be useful in the design of future systems for similar applications. It is primarily applicable to manned aircraft. It presents the basic characteristics, hardware descriptions, redundancy concepts, functional schematics, and discussions of the servo controls, failure monitoring, and fault tolerance. All existing FBW actuation systems are not described herein; however, those most representing the latest designs are included. While this AIR is intended as a reference source of information for aircraft actuation system designs, the exclusion or omission of any other appropriate actuation system or subsystem should not limit consideration of their use on future aircraft.
This SAE Standard applies only to new winches which are primarily designed for intermittent pulls and lifts and whose configuration and condition are the same as when they were shipped by the manufacturer. They are not intended to be used in any manner for the movement of personnel. They may be driven by any power source recommended by the manufacturer and will be capable of being powered in either direction. They will be equipped with an automatic safety brake system to control a load when lowering under power and positively hold a load when power is not being delivered to the winch. A hydraulic flow control valve or similar device may be used in the brake system to control a load when lowering under power. A clutch to release the drum for “free-spooling” may be provided and will be designed not to disengage itself under load. A drag brake may be provided to control “free-spooling,” but will not be relied on to control or hold a load. Power sources, such as hydraulic motors, even
Three levels of fan structural analysis are included in this practice: a Initial Structural Integrity b In-vehicle Testing c Durability (Laboratory) Test Methods The Initial Structural Integrity section describes analytical and test methods used to predict potential resonance and, therefore, possible fatigue accumulation. The In-vehicle (or machine) section enumerates the general procedure used to conduct a fan strain gage test. Various considerations that may affect the outcome of strain gage data have been described for the user of this procedure to adapt/discard depending on the particular application. The Durability Test Methods section describes the detailed test procedures for a laboratory environment that may be used depending on type of fan, equipment availability, and end objective. The second and third levels build upon information derived from the previous level. Engineering judgment is required as to the applicability of each level to a different vehicle environment or a
This SAE Aerospace Information Report (AIR) presents an overview of the application and control of fixed and variable displacement pumps with the emphasis on the controls most commonly used on variable displacement pumps. It describes various options to control the operation of hydraulic pumps in terms of controlling the pump output pressure and/or flow and assisting in the selection of the pump.
This report contains background information on life cycle cost elements and key ECS cost factors. Elements of life cycle costs are defined from initial design phases through operational use. Information on how ECS designs affect overall aircraft cost and information on primary factors affecting ECS costs are discussed. Key steps or efforts for comparing ECS designs on the basis of LCC are outlined. Brief descriptions of two computer programs for estimating LCC of total aircraft programs and their use to estimate ECS LCC, are included.
The cooling system with two fans is generally driven by electrical motors in the small cars. Compared with the traditional cars, heavy duty trucks have the larger heat dissipation power of cooling system. The motors power consumption of dual fans will be larger and the two electrical motors will occupy a large space in the engine cabin. Hydrostatic drive refers to the cooling fan is driven by hydraulic motor, but it has the low transmission efficiency. According to the engine water temperature value and the actual working status of the hydraulic system, the actual speed of cooling fan can be controlled by the computer, which guarantees the normal working water temperature of the engine. Hydrostatic drive is generally applied to heavy vehicles, engineering machinery and excavators as driving source of cooling fan which contains the advantages of large output power, overload protection, continuous speed regulation and flexible space arrangements. Integrating the characteristics of the
In this paper a new pressure control method of a modified accumulator-type Electro-hydraulic Braking System (EHB) is proposed. The system is composed of a hydraulic motor pump, an accumulator, an integrated master cylinder, a pedal feel simulator, valves and pipelines. Two pressurizing modes are switched between by-motor and by-accumulator to adapt different pressure boost demands. A differentiator filtering raw sensor signal and calculating pedal speed is designed. By using the pedal feel simulator, the relationship between wheel pressures and brake force is decoupled. The relationships among pedal displacement, pedal force and wheel pressure are calibrated by experiments. A model-based PI controller with predictor is designed to lower the influences caused by delay. Moreover, a self-tuning regulator is introduced to deal with the parameter’s time-varying caused by temperature, brake pads wearing and delay variation. To verify the controller validity, a Rapid Control Prototype (RCP
The heavy duty trucks have large engine power and drive continuously in mountainous area, so the heat dissipation of engine is very important. In the traditional cooling system with fixed transmission ratio fan, the cooling capacity is insufficient and the engine is easy to be over-heated when the engine is working in low speed and heavy load conditions. Owning to the bigger size of electric motor compared to the hydraulic motor, it is not suitably applied to the heavy duty trucks. Contrasted with the electric motor, the hydraulic drive cooling system is widely applied in heavy duty trucks due to smaller size, larger power, continuous speed modulation and flexible installation location. However, the low transmission efficiency of the pump-motor system results in high power consumption of the cooling system. In this paper, the mathematical and simulation model of hydraulic-driven fan cooling system is established for the specific engine. The study applies the digital PID controller of
This SAE Aerospace Information Report (AIR) applies to landing gear tires and airframe structure for all types and models of civil and military aircraft having tires as part of the landing gear.
It is important for engineering firms to be able to develop forecasts of recommended courses of action based on available information. In particular, engineering firms must be able to assess the benefit of performing information-gathering actions. For example, an automobile manufacturer may use a computer simulation of a hydraulic motor and pump in the design of a new vehicle. The model may contain random variables that can be more accurately determined through expensive information-gathering actions, e.g., physical experiments, surveys, etc. To decide whether to perform these information-gathering actions, the automobile manufacturer must be able to quantify the expected value to the firm of conducting them. However, the cost of computing the expected value of information (through optimization, Monte Carlo sampling, etc.) grows exponentially with the amount of information that is to be gathered and can often exceed the cost of actually gathering the information. Thus, if information
Nowadays, off-highway vehicles enjoyed a significant status in the national defense and civil construction. There is no doubt that the working conditions of off-highways are quite different from the conventional passenger cars, hence, their suspensions are particularly designed. Since the hydro-pneumatic suspension technology is maturely applied in engineering machinery, this paper presents a concept for a novel energy-harvesting device, which is applied in off-highway vehicles based on hydro-pneumatic suspension, namely, electro-hydraulic energy-harvesting suspension (EHEHS). The EHEHS took the fundamental of mechanism-electronic-hydraulic system, which consisted the following elements: a cylinder, 2 check valves, a hydro-pneumatic spring, a hydraulic motor, a DC motor, a processing circuit and a battery. In the EHEHS system, the cylinder is used to transmit the vibration energy into hydraulic energy, which is stored in hydro-pneumatic spring. The hydraulic motor is the energy
This SAE Aerospace Recommended Practice (ARP) is an application guide for hydraulic power transfer units and describes: The various types Typical design approaches Their operational characteristics and limitations Circuit recommendations Typical applications The scope of this ARP is limited to devices that transfer power between hydraulic systems and do so by means of rotary subassemblies such as hydraulic motors and pumps.
This SAE Aerospace Recommended Practice (ARP) establishes the factors which should be considered in the design and installation of a commercial transport rotorcraft hydraulic system, including the applicable airworthiness regulations that affect the hydraulic system. This ARP also provides information and guidelines on the many factors that arise in the design process to provide cost effectiveness, reliability, maintainability and accepted design and installation practices.
Due to the high demand of fuel efficient construction equipment, significant research effort has been dedicated to improving excavator efficiency. Among various possibilities, methods to recuperate energy during cab swing motion have been widely examined. Electric and hydraulic hybrids designs have shown to greatly improve fuel efficiency but require drastic design changes. The redesigned systems thus require many hours of operation to offset the manufacturing costs with fuel savings. In this research, a relatively simple swing energy recuperation system is presented using an additional accumulator, fixed displacement hydraulic motor, and control valves. With the system, hydraulic fluid is stored in an accumulator, and a simple controller opens a valve to allow the stored energy to assist the engine in running the main pumps. Using various accumulator capacity and hydraulic motor displacement combinations, the recuperation system was simulated for six cycles of a digging and dumping
This SAE Aerospace Information Report (AIR) establishes the specifications and descriptions of the critical components and operational guidelines for the standard hydraulic impulse machine for testing hydraulic hose assemblies, tubing, coils, fittings and similar fluid system components. This revision to the AIR1228 provides a description of a system that meets the requirements for specifications including: AS603, AS4265, and ARP1383. This impulse system utilizes closed loop servo control with specifically generated command signal waveforms. Data accuracy and integrity are emphasized in this revision. Knowing the uncertainty of the pressure measurement is important whether using a resonator tube system, as described in the original release of this document, or a closed-loop systems as described in this release. The accuracy of the data measurement system and consistency of the pressure waveform are fundamental to test validity, regardless of the system type. This is discussed in more
This SAE Aerospace Recommended Practice (ARP) is an application guide for fixed and variable displacement hydraulic motors. It provides details of the characteristics of fixed and variable displacement hydraulic motors, architectures, circuit designs, controls, and typical applications. The applications include airborne and defense vehicles with emphasis on high performance applications.
This document applies to special purpose equipment which is used in the ground handling, servicing, and maintenance of transport aircraft. Fixed airport facilities and equipment covered under other sections of Part 1910 of Code of Federal Regulations (OSHA) are excluded from the scope of this document.
This SAE Recommended Practice provides guidance for defining the requirements for evaluating hydraulic pumps and motors and for preparing detailed specifications for these components. The user can follow this document to set forth the pump and motor environmental and performance considerations, establish service life and reliability goals, and define specific evaluation tests for marine vehicle applications.
This procedure will be generally applicable to three classes of hydraulic components as listed below:
This SAE Aerospace Recommended Practice (ARP) provides guidance for the design and installation of a commercial aircraft hydraulic system to meet the applicable requirements, including the applicable airworthiness regulations that affect the hydraulic system design. This ARP also provides information and guidelines on the many factors that arise in the design process to provide cost effectiveness, reliability, maintainability and accepted design and installation practices.
Gas compressors (air and other compressible fluids) have been used sporadically since the 1940's for various utility functions in aerospace applications. They have been used to provide power to gun purge and drive systems, engine or APU starters (recharge accumulators), reservoir pressurization, cockpit pressurization, braking systems, canopy seals, engine control devices, landing gear activation, and boosted flight controls (see Table 1). In current state-of-the-art aircraft, most pneumatic system power is extracted from a stage of compression in the turbo-jet engine. As more and more demands are put on new generation engines for fuel economy and performance there is an increasing need for a new source of pneumatic power. This document is intended to describe current state-of-the-art technology in compressors, define the limitations, discuss enhancements needed and attempt to predict the needs of the future.
Much of the available long-term storage test data has been reviewed and topically separated to enable the independent discussion of storage effects on fluids, seals, hydraulic components, and hydraulic systems. Comments are made in Section 4 concerning the applicability of the test results and regarding design practices for storability. Conclusions are drawn in Section 5 regarding inactive storage of hydraulic systems for at least a 7 year period.
Fluid pressure pulsation in a fluid system is an inherent consideration in applications such as aircraft engine and control systems where mechanical component fatigue life and flow performance are critical. Positive displacement pumps transmitting fluid through hydraulic lines under high pressure impart periodic flow pulses to the fluid which can induce undesirable pressure ripple. Some failures of advanced aircraft prototype hardware were traced to a break in the hydraulic component of the control system due to severe localized responses to periodic pressure pulsations produced by a pump flow-induced ripple at the system resonant frequency. This response is associated with a strong structural fluid resonance that is not sufficiently damped by fluid leakage internal to the aircraft hydraulic system. In the case of pumps or hydraulic motors the main source of pulsation energy is in the flow-induced pressure wave associated with the system plumbing pressure pulsations. The pressure wave
Hydraulic systems are used on marine vehicles for steering, vehicle control, and utility services. System components that generate and transmit noise are of concern. This SAE Information Report (a) addresses noise requirements which may apply to the hydraulic systems of ships and submersibles, and (b) identifies noise sources and techniques which may be used to reduce system noise. Noise of power sources (e.g., electric motors) and end items (e.g., steering linkages) is beyond the scope of this document.
The marine environment differs greatly from other environments in which hydraulics are used. This Recommended Practice provides hydraulic design considerations and criteria for the marine environment and is applicable to commercial vessels, military ships, and submersible vehicles. This document may be used for manned and un-manned vehicles.
In order to reduce fuel consumption, companies have been looking at hybridizing vehicles. So far, two main hybridization options have been considered: electric and hydraulic hybrids. Because of light duty vehicle operating conditions and the high energy density of batteries, electric hybrids are being widely used for cars. However, companies are still evaluating both hybridization options for medium and heavy duty vehicles. Trucks generally demand very large regenerative power and frequent stop-and-go. In that situation, hydraulic systems could offer an advantage over electric drive systems because the hydraulic motor and accumulator can handle high power with small volume capacity. This study compares the fuel displacement of class 6 trucks using a hydraulic system compared to conventional and hybrid electric vehicles. The paper will describe the component technology and sizes of each powertrain as well as their overall vehicle level control strategies. The fuel consumption will be
To describe laboratory methods for determining and reporting the contaminant level of the wetted portion of hydraulic fluid power components, parts, subsystems and systems, and of fill fluids. For each type of item it provides a method of obtaining the liquid sample and the contamination level thereof. It also includes procedures for establishing a sampling plan and guidelines for establishing levels of acceptance, but does not set those levels.
The purpose of this aerospace information report is to provide a listing of national and international metric standards for use in aerospace fluid systems with their equivalent SAE inch, International ISO, and European AECMA standards.
This SAE Aerospace Information Report (AIR) presents a review of the types and general characteristics of power sources that may be used to provide the power for gaseous or liquid fluidic control systems. Fluidic definitions, terminology, units and symbols are defined in Reference 2.1.1.
This SAE Recommended Practice defines minimum requirements for general characteristics, performance, and durability. It is applicable to remanufactured assemblies (factory rebuild) only. This document applies to master cylinder assemblies and components of current established designs but does not cover fluid level sensors, integral proportioning valves, or those master cylinders used in anti-lock brake or traction control systems. These will be covered by other standards. The general characteristics and test procedure are specified in SAE J1693.
This SAE Standard describes a uniform method to calculate and specify travel performance characteristics of hydraulic excavators, material handlers, knuckle boom log loaders, delimbers, feller bunchers, harvesters, processors, and other knuckle boom material handlers. It establishes definitions and specifies machine conditions for calculations and tests. This document applies to crawler mounted machines such as hydraulic excavators as defined in SAE J/ISO 6165 and ISO 7135, and knuckle boom log loaders as defined in SAE J1209 and SAE J2055. This document also applies to certain forestry equipment defined in SAE J1209 and ISO 6814 that have crawler mountings such as delimbers, feller bunchers, harvesters, and processors. Included in the definition of hydraulic excavators are also front shovel, clamshell, and telescoping boom excavators.
This Aerospace Standard (AS) presents a system of graphic symbols intended primarily for usage in hydraulic and pneumatic system schematic diagrams for all types of aircraft. It is also considered suitable for marine vehicles and other applications and for ancillary documents where schematics are required. Individual graphic symbols shown herein are also considered suitable for use in conjunction with other types of symbols. This AS is intended to promote industry-wide acceptance and understanding of uniform standards and employs, where possible, symbols which are internationally recognized.
This standard is applicable to off-road work machines - base machine and its equipment included in categories 1.1, 1.2, 2, 4, and 5 of SAE J1116.
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